High Quality Strained Ge Epilayers on a Si[sub 0.2]Ge[sub 0.8]/Ge/Si(100) Global Strain-Tuning Platform

High structural quality, compressively strained Ge surface epilayers have been grown on Si(100) substrates of up to 200 mm diameter. The epitaxial growth by industrially compatible reduced pressure chemical vapor deposition proceeded uninterruptedly via an intermediate relaxed buffer. In-depth characterization of the epilayers revealed a relatively smooth surface and a low threading dislocation density. The Ge layers were demonstrated to remain fully strained for thicknesses of more than 100 nm. The high quality of the material and flexibility to choose the Ge layer thickness over a wide range make these heterostructures very attractive for fabricating various electronic and photonic devices.